Humans are omnivores. Means we eat plants AND meat. We don't eat just one or the other.
However statistically our ancestors were more fruit & vegetable & nut/seed eaters than meat eaters because the effort to track & kill prey animals would've been far, far more difficult.
Even African lions only have a success rate of 30% in a pride. That means 70% of the time they don't eat. Wolves have a 20% success rate - means 80% of the time they don't eat.
You'd have to be extremely stupid to think ancient humans ate meat beyond a rarity.
High meat diets are actually quite determential. Constant consumption of beef & other red meats makes you highly suspectable to heart disease. Even if you're fit otherwise it's not good for you --- it'll just mean you'll develop avoidable heart problems later.
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High meat diets due to the supportive minerals (e. g. zinc, Vitamin D) for testosterone, etc. means that you are actually more prone to aggressive violent behavior.
This is even found in animals - chimpanzee troops were the members eat more meat than usual are more violent & have problems with their behavior conduct. Such chimps are studied separately to other chimp troops because they are abnormal.
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And populations with more vegetable / fruit / seed/nut based diets are statistically smarter than those with high meat consumption. Unfortunately this is hard to prove as such countries are usually overpopulated.
However an obvious example is Japan. An advanced country. Low crime rate. High education level.
America is what it is. Extremely high crime rate. Moderate to lower education level.
The average Japanese eats 6.2kgs of beef per year.
The average American consumes 22.5kg of beef per year.
